Java Technology - A Comprehensive Introduction

Well-known for dominating as the third most popular programming language in the world, Java technology is a widely used programming language and computing platform created for developing and deploying applications of different types. Making it easier for developers to build and maintain applications, Java was launched in 1995 by Sun Microsystems completing their aim of creating a platform-independent language. This made it easier to develop web-based applications that can run on any operating system, leading to its significant role in shaping the digital landscape

Java was launched with the "write once, run anywhere" (WORA) philosophy, which means that Java code can run on any device that has a Java Virtual Machine (JVM). This provides a level of platform independence that has contributed to its widespread use. This feature has made Java a popular choice for developing a diverse range of applications, from web and mobile applications to enterprise-level systems.

One of Java's key strengths lies in its portability and robustness. Java programs are suitable for developing large-scale applications in various domains because they are designed to be secure, reliable, and scalable. The language's object-oriented nature also fosters reusable code.

Fundamentals of Java

Here are some factors that contributed to Java’s rise as one of the most demanded programming languages -

• Object-Oriented Programming (OOP): Being an object-oriented programming language, Java supports principles like encapsulation, inheritance, and polymorphism. This promotes modular and reusable code which helps in enhancing code organization and design.
  

• Multithreading: Java allows the concurrent execution of multiple threads, by providing built-in support for multithreading. This enhances the efficiency of applications by enabling them to perform multiple tasks simultaneously.

• Security: Java incorporates robust security features that contribute to creating secure Java applications. These include a Security Manager that defines access controls, bytecode verification during class loading, and a sandbox model for executing untrusted code.

• Platform Independent: Java code is compiled into an intermediate bytecode, allowing it to run on any device with a Java Virtual Machine (JVM). Java’s platform independence enables Java to be compatible across platforms, which is its fundamental feature.

• Extensive Standard Library: Java comes with a rich standard library that provides an extensive range of pre-built packages and classes. The availability of the library assists programmers by offering ready-to-use components for networking, data structures, and more.

• Strongly Typed Language: Java requires explicit declaration of variable types, which assists in enhancing code reliability. Code Example – // Strongly typed variable declaration int count = 5; String message = "Hello, Java!";

• Automatic Memory Management: Java includes the feature of automatic garbage collection, and managing memory which in turn reduces the risk of memory leaks.

How does a Java Program work?

From writing code to executing it, Java programs work through several steps that include the components of Java Technology including its development tools, Application Programming Interface (APIs), deployment technologies, user interface toolkits, and integrated libraries. Here’s an overview of how a Java program works:

Writing Java Code

The first step of creating a Java Program starts with writing code in a file with a ‘.java’ extension. This can be done through a text editor or an Integrated Environment (IDE). Whereas text editors like Notepad or Visual Studio Code give a basic environment for writing code, an IDE like Eclipse, IntelliJ IDEA, or NetBeans provides more features like code completion, debugging, and project management.

The basic structure of Java includes a class declaration, a main method and actual code within the curly braces-

public class HelloWorld {

public static void main(String[] args) {

System.out.println("Hello, World!");

}

}

Compiling Code through the Javac Compiler

The Java Compiler ‘javac’ is essential for running a Java Program. It is responsible for translating a high-level language like Java into Byte Code which is an intermediate form. Developers write source code to implement the logic and behavior of their programs in a file with a ‘.java’ extension adhering to the syntax and conventions of the Java Language. This source code is readable for humans but cannot be executed. The Java compiler converts it into bytecode which can be run by the Java Virtual Machine (JVM)

Executing Code by JVM

The Java Virtual Machine is an essential element in executing a Java Program. Once the source code is converted into byte code, JVM runs Just-In-Time (JIT) Compilation to translate it into machine code. This machine code is a set of instructions that can be understood by the computer and is usually unique to the machine’s unique architecture.

The JVM plays a pivotal role in achieving Java's platform independence. Regardless of the underlying operating system of hardware, Java Code can be used on any device with a compatible JVM by interpreting and compiling code at runtime.

Just before executing, JVM also loads and verifies the code for adhering to Java’s safety and security rules.

Navigating the Java Platform

The Java Platform is a software-only platform that can run on any Operating System like Linux, Windows, MacOS, etc. The Java Program includes the Java Virtual Machine and the Java Application Programming Interface (API). Java is a general-purpose, high-level, objectoriented programming language and a software platform for deploying applications.

It gives you the following features for your applications:

Development Tool: Java provides the development tools that help from compiling (javac) to running the application. It also includes documentation (Javadoc) tools for the easy development and testing of the applications.

API: The Application Programming Interface (API) is a ready-made package for accomplishing various tasks during programming. Java provides a large set the APIs to the developers, which assists in writing more concise code.

Deployment technologies: Java programming language provides many deployment technologies such as Web Start, Applets, etc. for easy deployment of the applications.

User Interfaces Toolkits: The Java Platform provides JavaFX, Swing, and Java 2D toolkits for easy development of GUI for applications.

Various Integration Libraries: There are many integration libraries used for the development of Java-based applications such as Java IDL API, JDBC API, Java Naming and Directory Interface (JNDI) API, Java RMI, and Java Remote Method Invocation over Internet Inter-ORB Protocol Technology (Java RMI-IIOP Technology).

Conclusion

In conclusion, Java technology, established in 1995 by Sun Microsystems, stands as the world's third most popular programming language, playing a pivotal role in shaping the digital landscape.

Fueled by the "write once, run anywhere" philosophy, Java's platform independence through the Java Virtual Machine (JVM) has made it a preferred choice for diverse applications. Its key strengths lie in portability, robustness, and the promotion of reusable code through object- oriented principles. From supporting multithreading to robust security features, Java's extensive standard library and strong typing enhance its appeal.

The journey from writing code to execution involves intricate steps, with the JVM ensuring safety and security. The Java platform, a versatile ecosystem encompassing development tools, APIs, and deployment technologies, underscores Java's commitment to providing a comprehensive environment for developers.

As technology evolves, Java remains a stalwart force, continuously influencing the development and deployment of robust and versatile applications.